Directional obstacle detecting cane for the blind



Nov. 24, 1964 w. A. RuTHvEN 3,158,851

DIRECTIONAL oBsTAcLE DETECTING CANE FoR THE BLIND Filed April 22, 196s 2 sheets-sheet 1 www Nov". 24, 1964 w, A. RUTHVEN 3,158,851

DIRECTIONAL OBSTACLE DETECTING CANE FOR THE BLIND Filed April 22, 1963 2 Sheets-Sheet 2 F1 /46 fa-q /a/ Vdi' A /5' L x )l 47 United States Patent O 3,158,351 DIRECTINAL (BBSTACLE DETECTING CANE FOR THE BLIND William A. Ruthven, 3 Fanok Road, Morristown, NJ. Filed Apr. 22, 1963, Ser. No. 274,457 Claims. (Cl. S40- 258) The invention relates in general to devices intended to protect blind persons when traveling on foot by aiding them in the detection of walking hazards in their path of movement, and has particularly reference to canes such as are commonly used for manual exploration of the way.

When out walking, a blind person usually contines his course to well traveled paths or sidewalks extending in his chosen direction of travel, but may cross streets bordered by curbs. The walking hazards likely to be encountered by a blind pedestrian may be divided into two general classes, viz.: (1) depressions in the path level, such as the drop from a curb to street level, descending steps, or a hole or ditch; and (2) obstacles that rise above the path level, such as the bottom one of ascending steps, a stone, brick or piece of lumber lying in the path, a fence, tree or bush close to one side of the path, the curb at the far side of a street being crossed, or the feet of another person standing or walking in front of him.

The canes customarily used by blind persons prior to my present invention do not afford the protection to be desired. The mode of use usually consists in tapping the path at a short distance directly in front of the users feet and occasionally to right and left of the center of the course. Supposing, for example, that the user of the cane cornes to a depression, class (l), such as the curb at the near side of a cross street. The tip, or foot, of the cane will slide over the edge of the curb and jump to the street surface at a point probably a foot beyond the curb. In that distance the duration of reaction time may be so great that the user will trip over the edge ofthe curb and fall or sprain his fankle. The same Will be true in an instance of a class (2) obstacle, such as the bottom step of a stairway. The cane will collide with `the obstacle abruptly and stop. The user, havinghad no time interval of warning, may fall forward onto the steps and bark his shins, at least.

It should now be apparent that the principal disadvantage of the prior art cane relied upon by blind persons is its failure to precede collision with a walking hazard by a warning signal of sufcient duration to permit the user to react safely to the warning.

It, therefore, is the primary object of the present invention to provide the blind-with an improved cane in the construction of which I have incorporated means which will communicate to the user a tactile and audible signal of sufficient duration preceding obstructive contact with a Walking hazard to enable him to halt his forward progress intime to avoid bodily injury.

To be more explicit, myy improved cane is equipped at or near its foot end with walking hazard exploratory means that project respectively straight ahead and laterally to right and left for contact with obstacles in the path of movement of the user. Each exploratory means is yieldable to a necessary degree from front to rear when in obstacle contact. Impulse transmission means is provided -to produce tactile and audible signals in the handle of the cane throughout the time interval' that each exploratory means is in contact with an obstacle. In most instances .the exploratory means is resilient in order that it may become restored automatically to operative condition after an obstacle has been passed by.

A fur-ther object of the invention is to cause the tactile indicator means to afford directional indications, i.e. whether the contacted obstacle is straight ahead or to the ice right or left of the course. To this end, the cane handle has distinct central, right and left portions carrying separately operable signal means.

Another object is to provide a cane for the blind which is equipped to perform all of the functions just enumerated, but which is simple and compact in construction, neat in appearance, light in weight, and capable of manufacture at low cost. k

Still further objects, advantages and features of the invention will become apparent as the following specific description is read in connection with the accompanying drawings, in which:

FIG. l is a side elevational view of the cane shownin the normal hand-grasped attitude of use; i

FIG. 2 is a front elevation thereof;

PIG. 3 is a wiring diagram showing the electrical elements of the device and the circuits therefor;

FIG. 4 is a largescale detail side elevation of the supporting wheel and foot end of the cane body, showing the latter broken away and in vertical section with the electric switch for said wheelin open position;

FIG. 5 is a similar View, showing Ithe switch closed;

FIG. 6 is a slightly enlarged horizontal cross-section on line 6 6 of FIG. l; Y p

FIG. 7 is a fragmentary front elevation of the cane body, showing one of the side-feeler walking hazard exploratory members in laterally extended operative position in solid lines and in collapsed inoperative position in broken lines; and

FIG. 8 is a vertical section on line 8--8 of FIG. 7

showing the friction locking joint for the collapsible member.

Referring now in detail to lthe drawings, wherein like reference characters designate corresponding parts'in the several views, FIG. 1 shows the cane in the attitude customarily assumed when hand-grasped by the user in his walking progress along a chosen path. The cane includes an elongated body 10 having a head end 11 and a foot end 12.

The head end 11 of body 10 is cross-shaped to provide respective laterally extending right and left handle portions 13 and 14 to support distinct right-hand and lefthand tactile indicator means 13 and 14. `Because of their capability of producing both tactile and audible signals, I have chosen electric vibrators, or buzzers, as the tactile indicator means for the handle portions of cane body 10. It is to be understood, however, that any equivalent means for this purpose may be substituted within the spirit and scope of my invention.

It may be explainedl at Vthis point that tactile indicator means 13 fand 14', respectively, will be energized by means to be described later herein when obstacles are encountered closely adjacent to the right and left sides of the users course of travel. Consequently, the buzzing sound of either `tactile indicator vibratorV will warn the user that some obstacle has been contacted. By spreading his cane-grasping hand to span both indicator means i3 and 14', the user can Vdetermine just what vibrator has been energized and thus distinguish between obstacles located at the right or left side of his course. For indication of obstacles lying directly in front of the user, I have provided a third tactile indicating vibrator 1S in a central position on handle 13-14.

At the foot end 12 of cane body 10, a walking hazard exploratory means 16 especially devised for detection of depressions is installed. (See FIGS. l, 2, 4 and 5.) This exploratory means 16 includes a ground-bearing and cane-supporting member preferably in the form of a wheel 17 journaled ina yoke 1? affixed toa rocker member 19 mounted on a transverse axle 2t) in casing 21 carried by said foot end 12 of cane body lil. Rocker member 19 carries a movable electrical contact 22 connected to one branch 23 or bus-wire of an electric circuit that includes a source of electric current 24 (see wiring diagram in FIG. 3), a manual switch 25, and the energizing coil of tactile indicator vibrator 15. rThe opposite br-anch 26 of the same circuit is connected to a stationary contact 27 operatively associated with movable contact 22 to form a normally open switch 23. `Wheel yoke 18 is affixed to rocker member 19 in a position eccentric to axle .20 such that movable contact 22 will be spaced directly below stationary contact 26 when wheel 17 is rolling on level ground and supporting the weight of the cane. This is the normally open condition of switch 28.

An -upwardly inclined skid 29 projects rearward from yoke 1S in rigid relation to the latter in a position to slide over the edge lof a depression, such as a street curb, when wheel 17 rolls off and drops, due to failure of ground support, into a position in which movable contact 22 rises against stationary contact 25 of switch 28 .to close the circuit of central vibrator and give warning of a depression directly `ahead of the users feet as he walks along.

A supplementary walking hazard exploratory means 30 for detection of obstacles that rise above the ground level directly ahead of the users feet, is illustrated in FIGS. l, 2 and 6. This exploratory means 30 includes a forwardly bowed feeler member 31 of resilient strip metal which is arranged to extend crosswise in front of the t'oot 12 of cane body 10 and has its base end pivotally attached at 32 for oscillation on a vertical axis to the frame of a Micro-switch 33 supported rigid-ly by casing 21. The base of feeler member 31 is electrically connected to the stationary contact 34 of switch 33 (FIG. 3) and is biased by spring means (not shown) into spaced open-contact relation to movable contact 35 of said switch. Feeler member 31 is in a position to collide with any upstanding obstacle and cause instantaneous closing of the electrical contacts of switch 33. The shape of feeler member 31 is such that it 1will yield rearwardly throughout a considerable horizontal distance and time interval following initial contact with an obstacle. This time interval should be sufficient to allow for safe reaction by the user of the cane.

Referring to the wiring diagram (FIG. 3), it will be observed that switch 33 is connected in parallel with switch 28.

For detection of obstacles located above ground level on either side of the path of movement of the users feet, I have provided distinct right-hand and left-hand walking hazard exploratory means at twoy levels, i.e. just above the foot 12 of cane body 10 and substantially midway of Said body. Identical exploratory means 36R and 361. respectively, yare positioned on they right and left sides of cane body 10 at the lower level, and 37R and 37L, respectively, on the right and left sides at the higher level. Each of these exploratory means 36R, SGL, 37R and 37L inz oludes a limber feeler member 38 of articulated construction, having a main arm 39 pivoted on a substantially horizontal foreandaft axis 39a to a substantially vertical base arm 4t), which latter in turn is pivotally supported on a lateral horizontal axis by a Micro-switch 41 carried by cane `body 10. Base arm 4d is electrically connected to the stationary contact 42 of the Micro-switch d1 (FIG. 3) and is biased by spring means (not shown) from Contact with the movable contact 43 thereof. In other words, the general arrangement of arm 4i? and the principal eleotrical elements of this Microswitch 41 is the same as the arrangement of the corresponding parts of the walking hazard exploratory means 36 disclosed in FIGS. l, 2 and 6. In this instance, however, main arm 39 is adapted to be swung on its pivotal axis 39a between operative position wherein it extends laterally from cane body 10 and inoperative position hanging close to said body, -as when the cane is not in use and possibly stored in-a hall closet. Some convenient means, such as a friction joint or clamping screw 391') (FIG. 8), ShOuld be PTGVded at the pivotal connection 33a of main arm 39 and base arm 40 to secure the said :main arm rigidly in either of its adjusted positions.

The switches for the respective walking hazard exploratory means 36K, 361i, 37K and 37L are designated 41LR, 41LL, 42UR and @UL (FIG. 3).

Right-hand tactile indicator vibrator 13 has one electrical terminal connected to the upper end of bus-wire 23 by conductor 44 and its other terminal connected by conductor 45 through switch dlLR to the lower end `of said bus wire and by conductor 46 through switch MUR to the said lower end of said bus wire, i.e. in bridging relation to source of electric current 2d. 0n the `opposite side of cane body 1t), left-hand tactile indicator vibrator 14 has one electrical terminal connected to the upper end of bus-wire 23 by conductor 47 and its other terminal connected by conductor 4,3 through switch 41LL to the lower end of said bus wire and by conductor 49 through switch 41UL to the said lower end of said bus wire; i.e. in bridging relation to source 24.

To complete the useful features of the cane, an electric blinker light 5, preferably red, is connected by a circuit 51 containing a manual switch 52 to bus'wire 23 in bridging relation to source 24.

Operation Before starting out for a walk with the protective aid of the improved cane, the user turns switch 25 into ON position and si 'ings main arms 39 of the respective walking hazard exploratory means 36K, 351s, 37R and 37L into horizontally extending opera-tive positions. Then, he grasps handle portions 13 and 14 with one hand in such a manner that his palm covers all three tactile indicator vibrators 13', 14 and 15.

Assuming that he arrives at the curb on the near side of a street, wheel 17 will jump the curb and skid 29 will slide over the edge of the latter until wheel 17 has landed on the street surface and ,is ready to roll forward again. While this is happening, the wheel assembly 17-18-19 will have rocked on axle 20 until switch 28 has closed and caused energization of Itactile indicator vibrator 15. Through the sense of touch in the center of the palm of his hand, the canes user will become aware of the curb contact, and the signal will persist for one or more seconds of time, which should be suicient for him to come to a stop before he can stumble over the curb and become injured. When his feet reach the curb, he can identify it with his feet and then proceed across the street. At this juncture, he can warn the drivers of vehicles and other pedestrains that a blind person is crossing the street by switching on red blinker light 50.

Assuming further that the user of the cane reaches the opposite curb safely, the feeler member 31 of supplementary walking hazard exploratory means 30 will contact the upstanding curb and be deflected rearwardly to close switch 33 and again energize tactile indicator vibrator 15. All the while feeler member 31 is yielding to curb contact, the tactile indicator signal will be warning of the obstacle encountered in time for safe reaction.

Should the canes user approach an upstanding obstacle closelyV adjacent to the path of movement of his feet at either side of said path, such as a wall, tree or rock, he will be warned by transmission of an electrical impulse from one of the walking hazard exploratory means 36K, 36L (for low obstacles) or 37R, 37L (for tall obstacles). For instance, if an obstacle at the right of the path is encountered, either exploratory means 36R, or both exploratory means 36K and 37K, (depending upon the height of the obstacle), will yield and close switches 41LR and/or 41UR, thereby energizing righthand tactile indicator Vibrator 13 and warning the user of an obstacle upstanding on his right. Similarly, collision of walking hazard exploratory means 36L and/or 37L with an upstanding obstacle on his left will yield 

1. A DIRECTIONAL OBSTACLE DETECTING CANE FOR BLIND PERSONS COMPRISING: AN ELONGATED CANE BODY HAVING HEAD AND FOOT ENDS; A HANDLE SECTION PROVIDED ON THE HEAD END OF THE CANE BODY; A TACTILE INDICATOR IN THE FORM OF AN ELECTRIC VIBRATOR MOUNTED ON SAID HANDLE SECTION; AN ELECTRIC CIRCUIT IN WHICH SAID VIBRATOR IS CONNECTED; NORMALLY OPEN SWITCH MEANS CONNECTED IN SAID ELECTRIC CIRCUIT AND INCLUDING STATIONARY AND MOVABLE CONTACTS; AND WALKING HAZARD EXPLORATORY MEANS SUPPORTED BY SAID CANE BODY AND INCLUDING A REARWARDLY YIELDABLE OBSTACLE CONTACTING MEMBER CONSTRUCTED AND ARRANGED 